Compound words are made when two or more words join (with or without a hyphen) to form a new word, and subsequently, a new meaning. Common English words are frequently combined to form compounds. Compound words exist in many languages and offer great insight into the inner workings of each language, including the basic building blocks such as suffixes, prefixes and word roots. Different parts of speech, such as nouns, verbs, adverbs and adjectives combine together to form compound words.
There are three different types of compound words: closed form, hyphenated form and open form. When two words are joined together to create a new meaning, they are said to be in closed form. For example: paperclip, carryover. The words that are joined together by a hyphen are in hyphenated form. For example: merry-go-round, well-being. In the open form, the words are open but when read together, a new meaning is formed. For example: high school, full moon.
We know that stress is important in pronunciation as it distinguishes between a compound noun and an adjective with a noun. With very few exceptions, English compound words are stressed on their first syllable.